📺 15 Questions for Evolutionists -- #10 How do 'living fossils' stay the same for millions of years?

Living fossils are fossilized animals and plants that look similar to modern organisms. Random mutations would have been occurring in creatures throughout such supposed vast time periods separating the assumed ancient and modern organisms. How then would 'living fossils' remain unchanged over supposed hundreds of millions of years, if evolution has changed worms into humans in the same time frame?